Equation 8 · Part 1 · Physics Optimizes, Evolution Satisfices: Two Kinds of Perfection
Symbol x_i
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is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
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is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
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The passage around this formula
a new position built only from the previous position and the local slope of fitness W at that exact point, with no access to the global shape of the landscape and no way to undo once it is fixed. In optimization-theory terms, the first rule is global by construction; the second is a greedy local rule that can only report the best it found from where it started. Physics gets to run the first kind of rule because a photon and a planet have no history to answer for. Selection is stuck running the second, forever, because every genome is a record of every place it has already been.
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A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.
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